Techniques for subcarrier tone reservation

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive an indication that tone reservation is to be applied to one or more subcarriers for one or more downlink communications. The UE may transmit one or more uplink signals, using the one or more subcarriers, for measurement by a base station. The UE may receive the one or more downlink communications having the tone reservation applied to the one or more subcarriers, the one or more subcarriers having tone reservation applied based at least in part on the measurement of the one or more uplink signals on the one or more subcarriers. Numerous other aspects are described.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for subcarrier tonereservation.

DESCRIPTION OF RELATED ART

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless network may include a number of base stations (BSs) that cansupport communication for a number of user equipment (UEs). A UE maycommunicate with a BS via the downlink and uplink. The downlink (orforward link) refers to the communication link from the BS to the UE,and the uplink (or reverse link) refers to the communication link fromthe UE to the BS. As will be described in more detail herein, a BS maybe referred to as a Node B, a gNB, an access point (AP), a radio head, atransmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, or thelike.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. NR, which may also be referred to as5G, is a set of enhancements to the LTE mobile standard promulgated bythe 3GPP. NR is designed to better support mobile broadband Internetaccess by improving spectral efficiency, lowering costs, improvingservices, making use of new spectrum, and better integrating with otheropen standards using orthogonal frequency division multiplexing (OFDM)with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDMand/or SC-FDM (e.g., also known as discrete Fourier transform spreadOFDM (DFT-s-OFDM)) on the uplink (UL), as well as supportingbeamforming, multiple-input multiple-output (MIMO) antenna technology,and carrier aggregation. As the demand for mobile broadband accesscontinues to increase, further improvements in LTE, NR, and other radioaccess technologies remain useful.

SUMMARY

In some aspects, a method of wireless communication performed by a userequipment (UE) includes receiving an indication that tone reservation isto be applied to one or more subcarriers for one or more downlinkcommunications; transmitting one or more uplink signals, using the oneor more subcarriers, for measurement by a base station; and receivingthe one or more downlink communications having the tone reservationapplied to the one or more subcarriers, the one or more subcarriershaving tone reservation applied based at least in part on themeasurement of the one or more uplink signals on the one or moresubcarriers.

In some aspects, the reception of the indication that tone reservationis to be applied to the one or more subcarriers for one or more downlinkcommunications comprises: receiving the indication that tone reservationis to be applied to the one or more subcarriers for one or more downlinkcommunications via one or more of: radio resource control signaling,medium access control signaling, or downlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the method includes determining a channel response ofthe one or more downlink communications; and determining that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers.

In some aspects, the determination of the channel response of the one ormore downlink communications comprises: determining the channel responsebased at least in part on demodulation reference signals of the one ormore downlink communications.

In some aspects, the determination that tone reservation is applied tothe one or more subcarriers based at least in part on received energy onthe one or more subcarriers comprises: determining that tone reservationis applied to the one or more subcarriers based at least in part on theone or more subcarriers having a lowest received energy of subcarriersof the one or more downlink communications.

In some aspects, the method includes decoding the one or more downlinkcommunication based at least in part on discarding samplings measured onto the one or more subcarriers.

In some aspects, the method includes transmitting an indication of ameasurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on reception of one or more downlink referencesignals.

In some aspects, a method of wireless communication performed by a basestation includes transmitting an indication that tone reservation is tobe applied to one or more subcarriers for one or more downlinkcommunications; receiving one or more uplink signals for measurement bya base station; and transmitting the one or more downlink communicationshaving tone reservation applied to the one or more subcarriers, the oneor more subcarriers having tone reservation applied based at least inpart on the measurement of the one or more uplink signals on the one ormore subcarriers.

In some aspects, the transmission of the indication that tonereservation is to be applied to the one or more subcarriers for one ormore downlink communications comprises: transmitting the indication thattone reservation is to be applied to the one or more subcarriers for oneor more downlink communications via one or more of: radio resourcecontrol signaling, medium access control signaling, or downlink controlinformation.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the method includes determining channel conditionsbased at least in part on the one or more uplink signals; and applyingtone reservation to the one or more subcarriers based at least in parton received energy, of the one or more uplink signals, on the one ormore subcarriers.

In some aspects, applying tone reservation to the one or moresubcarriers based at least in part on received energy, of the one ormore uplink signals, on the one or more subcarriers comprises: applyingtone reservation to the one or more subcarriers based at least in parton the one or more subcarriers having a lowest received energy ofsubcarriers of the one or more uplink signals.

In some aspects, the method includes receiving an indication of ameasurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on transmission of one or more downlink referencesignals, wherein the one or more subcarriers have tone reservationapplied based at least in part on the indication of the measurement ofthe one or more signal-to-interference-plus-noise ratios.

In some aspects, a UE for wireless communication includes a memory andone or more processors, operatively coupled to the memory, configuredto: receive an indication that tone reservation is to be applied to oneor more subcarriers for one or more downlink communications; transmitone or more uplink signals, using the one or more subcarriers, formeasurement by a base station; and receive the one or more downlinkcommunications having the tone reservation applied to the one or moresubcarriers, the one or more subcarriers having tone reservation appliedbased at least in part on the measurement of the one or more uplinksignals on the one or more subcarriers.

In some aspects, the one or more processors, when receiving theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications, are configured to:receive the indication that tone reservation is to be applied to the oneor more subcarriers for one or more downlink communications via one ormore of: radio resource control signaling, medium access controlsignaling, or downlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the one or more processors are further configured to:determine a channel response of the one or more downlink communications;and determine that tone reservation is applied to the one or moresubcarriers based at least in part on received energy on the one or moresubcarriers.

In some aspects, the one or more processors, when determining thechannel response of the one or more downlink communications, areconfigured to: determine the channel response based at least in part ondemodulation reference signals of the one or more downlinkcommunications.

In some aspects, the one or more processors, when determining that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers, are configuredto: determine that tone reservation is applied to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more downlinkcommunications.

In some aspects, the one or more processors are further configured to:decode the one or more downlink communication based at least in part ondiscarding signals associated with the one or more subcarriers.

In some aspects, the one or more processors are further configured to:transmit an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.

In some aspects, a base station for wireless communication includes amemory; and one or more processors, operatively coupled to the memory,configured to: transmit an indication that tone reservation is to beapplied to one or more subcarriers for one or more downlinkcommunications; receive one or more uplink signals for measurement by abase station; and transmit the one or more downlink communicationshaving tone reservation applied to the one or more subcarriers, the oneor more subcarriers having tone reservation applied based at least inpart on the measurement of the one or more uplink signals on the one ormore subcarriers.

In some aspects, the one or more processors, when transmitting theindication that tone reservation is to be Figapplied to the one or moresubcarriers for one or more downlink communications, are configured to:transmit the indication that tone reservation is to be applied to theone or more subcarriers for one or more downlink communications via oneor more of: radio resource control signaling, medium access controlsignaling, or downlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the one or more processors are further configured to:determine channel conditions based at least in part on the one or moreuplink signals; and apply tone reservation to the one or moresubcarriers based at least in part on received energy, of the one ormore uplink signals, on the one or more subcarriers.

In some aspects, the one or more processors, when applying tonereservation to the one or more subcarriers based at least in part onreceived energy, of the one or more uplink signals, on the one or moresubcarriers comprises: apply tone reservation to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more uplinksignals.

In some aspects, the one or more processors are further configured to:receive an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

In some aspects, a non-transitory computer-readable medium storing a setof instructions for wireless communication includes one or moreinstructions that, when executed by one or more processors of a UE,cause the UE to: receive an indication that tone reservation is to beapplied to one or more subcarriers for one or more downlinkcommunications; transmit one or more uplink signals, using the one ormore subcarriers, for measurement by a base station; and receive the oneor more downlink communications having the tone reservation applied tothe one or more subcarriers, the one or more subcarriers having tonereservation applied based at least in part on the measurement of the oneor more uplink signals on the one or more subcarriers.

In some aspects, the one or more instructions further cause the UE to:receive the indication that tone reservation is to be applied to the oneor more subcarriers for one or more downlink communications via one ormore of: radio resource control signaling, medium access controlsignaling, or downlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the one or more instructions further cause the UE to:determine a channel response of the one or more downlink communications;and determine that tone reservation is applied to the one or moresubcarriers based at least in part on received energy on the one or moresubcarriers.

In some aspects, the one or more instructions further cause the UE to:determine the channel response based at least in part on demodulationreference signals of the one or more downlink communications.

In some aspects, the one or more instructions further cause the UE to:determine that tone reservation is applied to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more downlinkcommunications.

In some aspects, the one or more instructions further cause the UE to:decode the one or more downlink communication based at least in part ondiscarding signals associated with the one or more subcarriers.

In some aspects, the one or more instructions further cause the UE to:transmit an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.

In some aspects, a non-transitory computer-readable medium storing a setof instructions for wireless communication includes one or moreinstructions that, when executed by one or more processors of a basestation, cause the base station to: transmit an indication that tonereservation is to be applied to one or more subcarriers for one or moredownlink communications; receive one or more uplink signals formeasurement by a base station; and transmit the one or more downlinkcommunications having tone reservation applied to the one or moresubcarriers, the one or more subcarriers having tone reservation appliedbased at least in part on the measurement of the one or more uplinksignals on the one or more subcarriers.

In some aspects, the one or more instructions further cause the basestation to: transmit the indication that tone reservation is to beapplied to the one or more subcarriers for one or more downlinkcommunications via one or more of: radio resource control signaling,medium access control signaling, or downlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the one or more instructions further cause the basestation to: determine channel conditions based at least in part on theone or more uplink signals; and apply tone reservation to the one ormore subcarriers based at least in part on received energy, of the oneor more uplink signals, on the one or more subcarriers.

In some aspects, the one or more instructions further cause the basestation to: apply tone reservation to the one or more subcarriers basedat least in part on the one or more subcarriers having a lowest receivedenergy of subcarriers of the one or more uplink signals.

In some aspects, the one or more instructions further cause the basestation to: receive an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

In some aspects, an apparatus for wireless communication includes meansfor receiving an indication that tone reservation is to be applied toone or more subcarriers for one or more downlink communications; meansfor transmitting one or more uplink signals, using the one or moresubcarriers, for measurement by a base station; and means for receivingthe one or more downlink communications having the tone reservationapplied to the one or more subcarriers, the one or more subcarriershaving tone reservation applied based at least in part on themeasurement of the one or more uplink signals on the one or moresubcarriers.

In some aspects, the apparatus includes means for receiving theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications via one or more of:radio resource control signaling, medium access control signaling, ordownlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the apparatus includes means for determining a channelresponse of the one or more downlink communications; and means fordetermining that tone reservation is applied to the one or moresubcarriers based at least in part on received energy on the one or moresubcarriers.

In some aspects, the apparatus includes means for determining thechannel response based at least in part on demodulation referencesignals of the one or more downlink communications.

In some aspects, the apparatus includes means for determining that tonereservation is applied to the one or more subcarriers based at least inpart on the one or more subcarriers having a lowest received energy ofsubcarriers of the one or more downlink communications.

In some aspects, the apparatus includes means for decoding the one ormore downlink communication based at least in part on discarding signalsassociated with the one or more subcarriers.

In some aspects, the apparatus includes means for transmitting anindication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.

In some aspects, an apparatus for wireless communication includes meansfor transmitting an indication that tone reservation is to be applied toone or more subcarriers for one or more downlink communications; meansfor receiving one or more uplink signals for measurement by a basestation; and means for transmitting the one or more downlinkcommunications having tone reservation applied to the one or moresubcarriers, the one or more subcarriers having tone reservation appliedbased at least in part on the measurement of the one or more uplinksignals on the one or more subcarriers.

In some aspects, the apparatus includes means for transmitting theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications via one or more of:radio resource control signaling, medium access control signaling, ordownlink control information.

In some aspects, the indication that tone reservation is to be appliedto the one or more subcarriers for the one or more downlinkcommunications comprises one or more of: an indication of a number ofsubcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied.

In some aspects, the one or more uplink signals comprise one or moresounding reference signals.

In some aspects, the apparatus includes means for determining channelconditions based at least in part on the one or more uplink signals; andmeans for applying tone reservation to the one or more subcarriers basedat least in part on received energy, of the one or more uplink signals,on the one or more subcarriers.

In some aspects, the apparatus includes means for applying tonereservation to the one or more subcarriers based at least in part on theone or more subcarriers having a lowest received energy of subcarriersof the one or more uplink signals.

In some aspects, the apparatus includes means for receiving anindication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and/or processing system assubstantially described herein with reference to and as illustrated bythe drawings and specification.

The foregoing has outlined, rather broadly, the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a diagram illustrating an example of a wireless network, inaccordance with the present disclosure.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a UE in a wireless network, in accordance with thepresent disclosure.

FIG. 3 is a diagram illustrating an example of subcarrier tonereservation, in accordance with the present disclosure.

FIGS. 4-6 are diagrams illustrating examples associated with subcarriertone reservation, in accordance with the present disclosure.

FIGS. 7 and 8 are diagrams illustrating example processes associatedwith subcarrier tone reservation, in accordance with the presentdisclosure.

FIGS. 9 and 10 are block diagrams of example apparatuses for wirelesscommunication, in accordance with the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with a 5G or NR radio access technology(RAT), aspects of the present disclosure can be applied to other RATs,such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

FIG. 1 is a diagram illustrating an example of a wireless network 100,in accordance with the present disclosure. The wireless network 100 maybe or may include elements of a 5G (NR) network and/or an LTE network,among other examples. The wireless network 100 may include a number ofbase stations 110 (shown as BS 110 a, BS 110 b, BS 110 c, and BS 110 d)and other network entities. A base station (BS) is an entity thatcommunicates with user equipment (UEs) and may also be referred to as anNR BS, a Node B, a gNB, a 5G node B (NB), an access point, a transmitreceive point (TRP), or the like. Each BS may provide communicationcoverage for a particular geographic area. In 3GPP, the term “cell” canrefer to a coverage area of a BS and/or a BS subsystem serving thiscoverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces, suchas a direct physical connection or a virtual network, using any suitabletransport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay BS 110 d may communicate with macro BS 110 a and a UE120 d in order to facilitate communication between BS 110 a and UE 120d. A relay BS may also be referred to as a relay station, a relay basestation, a relay, or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, such as macro BSs, pico BSs, femto BSs, relay BSs, orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, or the like. A UE may be a cellular phone(e.g., a smart phone), a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, atablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook,a medical device or equipment, biometric sensors/devices, wearabledevices (smart watches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, and/or location tags, that may communicate with a basestation, another device (e.g., remote device), or some other entity. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, and/or may be implemented as NB-IoT(narrowband internet of things) devices. Some UEs may be considered aCustomer Premises Equipment (CPE). UE 120 may be included inside ahousing that houses components of UE 120, such as processor componentsand/or memory components. In some aspects, the processor components andthe memory components may be coupled together. For example, theprocessor components (e.g., one or more processors) and the memorycomponents (e.g., a memory) may be operatively coupled, communicativelycoupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, or the like. A frequency may alsobe referred to as a carrier, a frequency channel, or the like. Eachfrequency may support a single RAT in a given geographic area in orderto avoid interference between wireless networks of different RATs. Insome cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol or avehicle-to-infrastructure (V2I) protocol), and/or a mesh network. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

Devices of wireless network 100 may communicate using theelectromagnetic spectrum, which may be subdivided based on frequency orwavelength into various classes, bands, channels, or the like. Forexample, devices of wireless network 100 may communicate using anoperating band having a first frequency range (FR1), which may span from410 MHz to 7.125 GHz, and/or may communicate using an operating bandhaving a second frequency range (FR2), which may span from 24.25 GHz to52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred toas mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 isoften referred to as a “millimeter wave” band despite being differentfrom the extremely high frequency (EHF) band (30 GHz-300 GHz) which isidentified by the International Telecommunications Union (ITU) as a“millimeter wave” band. Thus, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like, if usedherein, may broadly represent frequencies less than 6 GHz, frequencieswithin FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz).Similarly, unless specifically stated otherwise, it should be understoodthat the term “millimeter wave” or the like, if used herein, may broadlyrepresent frequencies within the EHF band, frequencies within FR2,and/or mid-band frequencies (e.g., less than 24.25 GHz). It iscontemplated that the frequencies included in FR1 and FR2 may bemodified, and techniques described herein are applicable to thosemodified frequency ranges.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1 .

FIG. 2 is a diagram illustrating an example 200 of a base station 110 incommunication with a UE 120 in a wireless network 100, in accordancewith the present disclosure. Base station 110 may be equipped with Tantennas 234 a through 234 t, and UE 120 may be equipped with R antennas252 a through 252 r, where in general T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI)) and control information (e.g.,CQI requests, grants, and/or upper layer signaling) and provide overheadsymbols and control symbols. Transmit processor 220 may also generatereference symbols for reference signals (e.g., a cell-specific referencesignal (CRS) or a demodulation reference signal (DMRS)) andsynchronization signals (e.g., a primary synchronization signal (PSS) ora secondary synchronization signal (SSS)). A transmit (TX)multiple-input multiple-output (MIMO) processor 230 may perform spatialprocessing (e.g., precoding) on the data symbols, the control symbols,the overhead symbols, and/or the reference symbols, if applicable, andmay provide T output symbol streams to T modulators (MODs) 232 a through232 t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM) to obtain an output sample stream. Each modulator 232may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all R demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulateand decode) the detected symbols, provide decoded data for UE 120 to adata sink 260, and provide decoded control information and systeminformation to a controller/processor 280. The term“controller/processor” may refer to one or more controllers, one or moreprocessors, or a combination thereof. A channel processor may determinea reference signal received power (RSRP) parameter, a received signalstrength indicator (RSSI) parameter, a reference signal received quality(RSRQ) parameter, an/or a CQI parameter, among other examples. In someaspects, one or more components of UE 120 may be included in a housing284.

Network controller 130 may include communication unit 294,controller/processor 290, and memory 292. Network controller 130 mayinclude, for example, one or more devices in a core network. Networkcontroller 130 may communicate with base station 110 via communicationunit 294.

Antennas (e.g., antennas 234 a through 234 t and/or antennas 252 athrough 252 r) may include, or may be included within, one or moreantenna panels, antenna groups, sets of antenna elements, and/or antennaarrays, among other examples. An antenna panel, an antenna group, a setof antenna elements, and/or an antenna array may include one or moreantenna elements. An antenna panel, an antenna group, a set of antennaelements, and/or an antenna array may include a set of coplanar antennaelements and/or a set of non-coplanar antenna elements. An antennapanel, an antenna group, a set of antenna elements, and/or an antennaarray may include antenna elements within a single housing and/orantenna elements within multiple housings. An antenna panel, an antennagroup, a set of antenna elements, and/or an antenna array may includeone or more antenna elements coupled to one or more transmission and/orreception components, such as one or more components of FIG. 2 .

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports that include RSRP, RSSI, RSRQ, and/or CQI) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In someaspects, a modulator and a demodulator (e.g., MOD/DEMOD 254) of the UE120 may be included in a modem of the UE 120. In some aspects, the UE120 includes a transceiver. The transceiver may include any combinationof antenna(s) 252, modulators and/or demodulators 254, MIMO detector256, receive processor 258, transmit processor 264, and/or TX MIMOprocessor 266. The transceiver may be used by a processor (e.g.,controller/processor 280) and memory 282 to perform aspects of any ofthe methods described herein.

At base station 110, the uplink signals from UE 120 and other UEs may bereceived by antennas 234, processed by demodulators 232, detected by aMIMO detector 236 if applicable, and further processed by a receiveprocessor 238 to obtain decoded data and control information sent by UE120. Receive processor 238 may provide the decoded data to a data sink239 and the decoded control information to controller/processor 240.Base station 110 may include communication unit 244 and communicate tonetwork controller 130 via communication unit 244. Base station 110 mayinclude a scheduler 246 to schedule UEs 120 for downlink and/or uplinkcommunications. In some aspects, a modulator and a demodulator (e.g.,MOD/DEMOD 232) of the base station 110 may be included in a modem of thebase station 110. In some aspects, the base station 110 includes atransceiver. The transceiver may include any combination of antenna(s)234, modulators and/or demodulators 232, MIMO detector 236, receiveprocessor 238, transmit processor 220, and/or TX MIMO processor 230. Thetransceiver may be used by a processor (e.g., controller/processor 240)and memory 242 to perform aspects of any of the methods describedherein.

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with subcarrier tone reservation, asdescribed in more detail elsewhere herein. For example,controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform or directoperations of, for example, process 700 of FIG. 7 , process 800 of FIG.8 , and/or other processes as described herein. Memories 242 and 282 maystore data and program codes for base station 110 and UE 120,respectively. In some aspects, memory 242 and/or memory 282 may includea non-transitory computer-readable medium storing one or moreinstructions (e.g., code and/or program code) for wirelesscommunication. For example, the one or more instructions, when executed(e.g., directly, or after compiling, converting, and/or interpreting) byone or more processors of the base station 110 and/or the UE 120, maycause the one or more processors, the UE 120, and/or the base station110 to perform or direct operations of, for example, process 700 of FIG.7 , process 800 of FIG. 8 , and/or other processes as described herein.In some aspects, executing instructions may include running theinstructions, converting the instructions, compiling the instructions,and/or interpreting the instructions.

In some aspects, the UE includes means for receiving an indication thattone reservation is to be applied to one or more subcarriers for one ormore downlink communications; means for transmitting one or more uplinksignals, using the one or more subcarriers, for measurement by a basestation; or means for receiving the one or more downlink communicationshaving the tone reservation applied to the one or more subcarriers, theone or more subcarriers having tone reservation applied based at leastin part on the measurement of the one or more uplink signals on the oneor more subcarriers. The means for the UE to perform operationsdescribed herein may include, for example, one or more of antenna 252,demodulator 254, MIMO detector 256, receive processor 258, transmitprocessor 264, TX MIMO processor 266, modulator 254,controller/processor 280, or memory 282.

In some aspects, the UE includes means for receiving the indication thattone reservation is to be applied to the one or more subcarriers for oneor more downlink communications via one or more of: radio resourcecontrol signaling, medium access control signaling, or downlink controlinformation.

In some aspects, the UE includes means for determining a channelresponse of the one or more downlink communications; or means fordetermining that tone reservation is applied to the one or moresubcarriers based at least in part on received energy on the one or moresubcarriers.

In some aspects, the UE includes means for determining the channelresponse based at least in part on demodulation reference signals of theone or more downlink communications.

In some aspects, the UE includes means for determining that tonereservation is applied to the one or more subcarriers based at least inpart on the one or more subcarriers having a lowest received energy ofsubcarriers of the one or more downlink communications.

In some aspects, the UE includes means for decoding the one or moredownlink communication based at least in part on discarding signalsassociated with the one or more subcarriers.

In some aspects, the UE includes means for transmitting an indication ofa measurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on reception of one or more downlink referencesignals.

In some aspects, the base station includes means for transmitting anindication that tone reservation is to be applied to one or moresubcarriers for one or more downlink communications; means for receivingone or more uplink signals for measurement by a base station; or meansfor transmitting the one or more downlink communications having tonereservation applied to the one or more subcarriers, the one or moresubcarriers having tone reservation applied based at least in part onthe measurement of the one or more uplink signals on the one or moresubcarriers. The means for the base station to perform operationsdescribed herein may include, for example, one or more of transmitprocessor 220, TX MIMO processor 230, modulator 232, antenna 234,demodulator 232, MIMO detector 236, receive processor 238,controller/processor 240, memory 242, or scheduler 246.

In some aspects, the base station includes means for transmitting theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications via one or more of:radio resource control signaling, medium access control signaling, ordownlink control information.

In some aspects, the base station includes means for determining channelconditions based at least in part on the one or more uplink signals; ormeans for applying tone reservation to the one or more subcarriers basedat least in part on received energy, of the one or more uplink signals,on the one or more subcarriers.

In some aspects, the base station includes means for applying tonereservation to the one or more subcarriers based at least in part on theone or more subcarriers having a lowest received energy of subcarriersof the one or more uplink signals.

In some aspects, the base station includes means for receiving anindication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2 .

FIG. 3 is a diagram illustrating an example 300 of UE subcarrier tonereservation on one or more subcarriers, in accordance with the presentdisclosure. In some networks, a base station may transmit a downlinktransmission on a physical downlink shared channel (PDSCH) with tonereservation on one or more subcarriers based at least in part onmeasurement(s) of uplink signals from a UE, a request from the UE, anindication of a capability of the UE, and/or an independentdetermination by the base station, among other examples (e.g., asdescribed herein).

In some aspects, the UE may be configured to communicate with the basestation with a configuration for tone reservation. For example, theconfiguration may be common for multiple communications (e.g., for aconfigured grant and/or semi-persistent scheduling resources), multipleUEs connected to the base station, a beam provided by the base station,a cell provided by the base station, and/or the like.

As shown by example 300, a PDSCH may include one or more reservedsubcarriers (e.g., tones) on which data and/or pilots are not to betransmitted. In some aspects, the subcarriers may be empty (e.g., nothaving any information intended for transmission to the UE).Additionally, or alternatively, tone reservation may be applied tophysical downlink control channel (PDCCH) symbols (e.g., symbols 0 and 1in FIG. 3 ). In some aspects, a pilot may include or may be a referencesignal. In some aspects, the base station may transmit a signal that isconfigured to improve a peak-to-average-power ratio (PAPR) for adownlink transmission on the PDSCH by using tone reservation to foregotransmission of data and/or pilots on the one or more reservedsubcarriers. While example 300 provides an example of tone reservationapplied to PDSCH and/or PDCCH, in some aspects (e.g., when a UE appliestone reservation to uplink communications transmitted to a basestation), tone reservation may be applied to PUSCH and/or PUCCH symbols.

The use of tone reservation may involve significant overhead that maydecrease overall throughput. For example, to enable the UE to identifywhich subcarriers to discard (e.g., the reserved subcarriers), the basestation may indicate the frequency locations (e.g., using identifiers)of the subcarriers to the UE. These indications may consumecommunication, network, and power resources (e.g., bits) for the basestation to transmit (e.g., in downlink control information) and for theUE to receive. Additionally, or alternatively, consumption of thenetwork resources for the indications may decrease throughput availablefor data (e.g., associated with the PDSCH). In a communication wheretone reservation is not used, an increase in PAPR may occur, which maydegrade communications between the base station and the UE, and maynegatively affect an efficiency of power amplification at the basestation. Based at least in part on degradation of the communications,the UE and/or the base station may consume power, communication,network, and computing resources to detect and/or correct communicationerrors associated with the degradation.

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3 .

In some aspects described herein, a base station may transmit anindication that tone reservation is to be applied to one or moresubcarriers for downlink communications, and a UE may receive theindication. The UE may transmit one or more uplink signals (e.g.,sounding reference signals (SRSs)), using the one or more subcarriers,for measurement by the base station. The base station may receive andmeasure the one or more uplink signals, such as by measuring asignal-to-interference-plus-noise ratio (SINR) and/or another channelparameter associated with received power (e.g., RSRP) and/or receivedenergy. The base station may determine which subcarriers should be usedfor tone reservation based at least in part on the measurements of theone or more uplink signals and/or an assumption of relatively highreciprocity between the uplink and downlink channels. The base stationmay transmit downlink communications with tone reservation applied tosubcarriers based at least in part on the measurement of the one or moreuplink signals. The UE may receive the downlink communications havingthe tone reservation applied. The UE may determine which subcarriers ofthe downlink communications have the tone reservation applied based atleast in part on received energies of the downlink communications asmeasured on subcarriers used for the downlink communications. In someaspects, the UE may determine a number of subchannels to which tonereservation is applied based at least in part on an indication from thebase station. For example, the UE may determine that tone reservation isapplied to subcarriers in a bottom 10% of received power based at leastin part on received energies of the downlink communication as measuredon subcarriers used for the downlink communications and based at leastin part on receiving an indication from the base station that tonereservation is a bottom 10% of subcarriers. The UE may discard samplesassociated with the subcarriers to which tone reservation is determinedto be applied.

In this way, the base station and UE may communicate using tonereservation without the need to transmit reports to identify subcarriersto which tone reservation is to be applied. This may reduce overheadassociated with the use of tone reservation by obviating the need totransmit reports for tone reservation, which may increase throughputbetween the UE and base station. In addition, the application of tonereservation may lead to improved PAPR, which may conserve resources thatthe UE uses to receive (e.g., demodulate and/or decode) the downlinktransmission and may also lead to improved efficiency of poweramplification at the base station (e.g., by conserving power that wouldotherwise be used to transmit signals using the reserved subcarriers).

FIG. 4 is a diagram illustrating an example 400 associated withsubcarrier tone reservation, in accordance with the present disclosure.As shown in FIG. 4 , a base station (e.g., base station 110) maycommunicate with a UE (e.g., UE 120). In some aspects, the base stationand the UE may be part of a wireless network (e.g., wireless network100). As shown in FIG. 4 , the base station may apply tone reservationfor downlink communications.

As show by reference number 405, the base station may transmit, and theUE may receive, configuration information. In some aspects, the UE mayreceive the configuration information via one or more of radio resourcecontrol (RRC) signaling, MAC control elements (MAC CEs), and/or downlinkcontrol information (DCI), among other examples. In some aspects, theconfiguration information may include an indication of one or moreconfiguration parameters (e.g., already known to the UE) for selectionby the UE, and/or explicit configuration information for the UE to useto configure the UE, among other examples.

In some aspects, the configuration information may indicate that the UEis to receive an indication that tone reservation is to be applied toone or more subcarriers for one or more downlink communications. Forexample, the configuration information may indicate that the UE is toreceive the indication via RRC signaling, MAC signaling, and/or DCI,among other examples. In some aspects, the indication may include anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, and/or a threshold power for subcarriers to which tonereservation is to be applied. In some aspects, the configurationinformation may indicate that the UE is to transmit one or more uplinksignals (e.g., sounding reference signals), using the one or moresubcarriers, for measurement by the base station. In some aspects, theconfiguration information may indicate that the UE is to determine achannel response of the one or more downlink communications (e.g., basedat least on part on demodulation reference signals of the one or moredownlink communications) and determine that tone reservation is appliedto the one or more subcarriers based at least in part on received energy(e.g., power) on the one or more subcarriers (e.g., based at least inpart on the one or more subcarriers having a lowest received energy ofsubcarriers of the one or more downlink communications).

In some aspects, the configuration information may indicate that the UEis to receive the one or more downlink communications having the tonereservation applied to the one or more subcarriers and that the one ormore subcarriers have had tone reservation applied based at least inpart on the measurement (e.g., by the base station) of the one or moreuplink signals on the one or more subcarriers. In some aspects, theconfiguration information may indicate that the UE is to decode the oneor more downlink communications based at least in part on discardingsamples measured on the one or more subcarriers (e.g., zeroing out loglikelihood ratios (LLRs) for the one or more subcarriers). In someaspects, the configuration information may indicate that the UE is totransmit an indication of a measurement of one or moresignal-to-interference-plus-noise ratios (SINRs) based at least in parton reception of one or more downlink reference signals.

As shown by reference number 410, the UE may configure itself based atleast in part on the configuration information. In some aspects, the UEmay be configured to perform one or more operations described hereinbased at least in part on the configuration information.

As shown by reference number 415, the UE may transmit, and the basestation may receive, an indication of a UE capability to receivedownlink communications having tone reservation applied based at leastin part on one or more measurements of uplink signals. In some aspects,the UE may transmit the indication as part of an RRC configurationprocess. For example, the UE may transmit the indication in connectionwith a UE capability report during or after an RRC configurationprocess. In some aspects, the UE capability to receive the downlinkcommunications having the tone reservation applied may be based at leastin part on a configuration of the UE, components of the UE, and/oravailability of resources of the UE that may be used to determinesubchannels to which tone reservation has been applied within athreshold amount of time.

As shown by reference number 420, the base station may transmit, and theUE may receive, one or more downlink signals, such as one or moredownlink reference signals. In some aspects, the base station maytransmit one or more channel state information reference signals(CSI-RSs) and/or one or more synchronization signal blocks (SSBs), amongother examples, for the UE to measure. The UE may measure the one ormore downlink signals to determine one or more SINRs associated with oneor more channels via which the UE receives communications from the basestation.

As shown by reference number 425, the UE may transmit, and the basestation may receive, a measurement report. In some aspects, the UE maytransmit, and the base station may receive, a measurement of one or moreSINRs that are based at least in part on reception of the one or moredownlink signals. In some aspects, the base station may determinewhether to use tone reservation for subsequent downlink communicationsbased at least in part on the measurement report. For example, the basestation may determine to use tone reservation based at least in part ona relatively low SINR (e.g., less than or equal to a threshold) and/ormay determine to not use tone reservation based at least in part on arelatively high SINR (e.g., greater than or equal to a threshold). Insome aspects, the base station may determine an amount (e.g., a level ora degree) of tone reservation to apply based at least in part on themeasurement report. For example, the base station may determine a numberof subcarriers to which tone reservation is to be applied, a fraction ofsubcarriers to which tone reservation is to be applied, or a thresholdpower for subcarriers to which tone reservation is to be applied basedat least in part on the one or more SINRs indicated in the measurementreport.

As shown by reference number 430, the base station may transmit, and theUE may receive, an indication that tone reservation is to be applied tosubcarrier(s) for downlink communication(s). In some aspects, the UE mayreceive the indication (e.g., MAC-CE with a slot offset between adownlink allocation and corresponding data (KO) greater than or equal to0) via RRC signaling, MAC signaling, and/or DCI, among other examples.

In some aspects, the indication that tone reservation is to be appliedmay include an indication of a number of subcarriers to which tonereservation is to be applied, a fraction (e.g., percentage) ofsubcarriers to which tone reservation is to be applied, and/or athreshold power for subcarriers to which tone reservation is to beapplied, among other examples. For example, the indication may includeinformation that indicates that the N subcarriers with the lowest energyand/or power (e.g., based on signal-to-noise ratio (SNR) measurements,SINR measurements, and/or RSSI measurements) are to have tonereservation applied, where N is a positive integer. As another example,the indication may include information that indicates a fraction orpercentage (e.g., one fourth, one tenth, 5%, 10%, 20%, or the like) ofsubcarriers to which tone reservation is to be applied (e.g.,subcarriers in the bottom fourth, tenth, 5%, 10%, 20%, or the like, inenergy and/or power). As yet another example, the indication may includeinformation that indicates a threshold power (e.g., 0 dB, −5 dB, −10 dB,or the like), and that tone reservation is to be applied to subcarriersassociated with uplink signals that fail to satisfy the threshold power.

In some aspects, the indication that tone reservation is to be appliedmay include information identifying a tone reservation optimizationtechnique or formula. For example, based at least in part on the numberof subcarriers, the fraction of subcarriers, and/or the threshold powerfor subcarriers to which tone reservation is to be applied, anoptimization technique may be designed to identify subcarriers for tonereservation in a manner that optimizes PAPR with a constraint of amaximum power (e.g., transmit power) that is equal to the power used forthe PDSCH and/or PUCCH subcarrier. In some aspects, the indication mayinclude information that indicates that tone reservation optimizationtechniques are to be performed in iterations, are to be generated byapplying machine learning, are to be generated using constrained orunconstrained optimization, or are to be generated by testing hypothesisiterations, among other examples. In some aspects, the indication mayinclude information identifying a minimum tone reservation powerconstraint to be used (e.g., in a manner designed to improve UEdetection).

In some aspects, the indication that tone reservation is to be appliedmay include information identifying a PAPR threshold to be achieved bytone reservation, and may include information indicating that varioustone reservation and/or optimization techniques are to be used until thePAPR threshold is satisfied. For example, the indication may includeinformation identifying the PAPR threshold and information indicatingthat the lowest energy subcarriers are to be iteratively discarded untilthe PAPR threshold is reached (e.g., starting with discarding the lowest1% of subcarriers and incrementing by +1% until the PAPR threshold issatisfied).

As shown by reference number 435, the UE may transmit, and the basestation may receive, one or more uplink signals. In some aspects, theone or more uplink signals may be transmitted by the UE for measurementby the base station (e.g., to enable the base station to identifysubcarriers to which tone reservation is to be applied). In someaspects, the one or more uplink signals include one or more soundingreference signals (SRSs).

As shown by reference number 440, the base station may apply tonereservation to subcarrier(s) based at least in part on received energyon the one or more uplink signals. In some aspects, the base station maydetermine channel conditions (e.g., received energy measurements, SINRvalue(s), and/or PAPR value(s), among other examples) based at least inpart on the one or more uplink signals and apply tone reservation basedat least in part on the channel conditions. In some aspects, the basestation may apply tone reservation to the subcarrier(s) based at leastin part on the subcarrier(s) having a lowest received energy ofsubcarriers of the one or more uplink signals. In some aspects, the basestation may apply tone reservation based at least in part on receivingthe indication of the measurement of one or more SINRs (e.g., themeasurement report described in connection with reference number 425)and/or based at least in part on transmission of one or more downlinkreference signals (e.g., the downlink signals described in connectionwith reference number 420).

In some aspects, the base station may apply tone reservation to a numberof subcarriers, a fraction (e.g., percentage) of subcarriers, and/orbased at least in part on a threshold power for subcarriers, among otherexamples (e.g., as described herein). In some aspects, the base stationmay apply tone reservation using a tone reservation optimizationtechnique (e.g., as described herein). In some aspects, the base stationmay apply tone reservation based at least in part on a PAPR thresholdand/or various tone reservation and/or optimization techniques to beiteratively used until the PAPR threshold is satisfied (e.g., asdescribed herein).

In some aspects, the base station may prepare a UE report indicatingwhether tone reservation is applied and indicating a number ofsubcarrier(s) (e.g., fraction or percentage) to which tone reservationis applied. In some aspects, the tone reservation frequency locations(e.g., subcarrier identifiers) and corresponding values may beidentified to a mapper, along with data and/or pilots for transmissionto the UE (e.g., using OFDM transmission protocol (e.g., IFFT)). Themapper may map the data and/or pilots to subcarriers of the channel,excluding subcarriers to which tone reservation is applied.

As shown by reference number 445, the base station may transmit, and theUE may receive, downlink communication(s) having the tone reservationapplied to the subcarrier(s). In some aspects, subcarrier(s) to whichtone reservation is applied (e.g., by the base station) are based atleast in part on the measurement of the one or more uplink signals onthe subcarrier(s) (e.g., as described herein).

As shown by reference number 450, the UE may determine a channelresponse of the downlink communication(s) and/or that tone reservationis applied to the subcarrier(s) based at least in part on receivedenergy on the subcarrier(s). In some aspects, the UE may determine thattone reservation is applied to the downlink communication(s) based atleast in part on the configuration information (e.g., described above inconnection with reference number 405), the indication that tonereservation is to be applied (e.g., described above in connection withreference number 430), and/or a UE report included in the downlinkcommunication(s) (e.g., described above in connection with referencenumber 440), among other examples. In some aspects, the UE may determinethe channel response based at least in part on DMRSs of the downlinkcommunication(s) (e.g., based at least in part on an estimation of thelowest energy subcarriers using the DMRSs).

In some aspects, the UE may determine that tone reservation is appliedto the subcarrier(s) based at least in part on the subcarrier(s) havinga lowest received energy of subcarriers used for the one or moredownlink communications. In some aspects, the UE may determine that tonereservation is applied to the subcarrier(s) based at least in part oninformation included in the indication that tone reservation is to beapplied to the subcarrier(s) (e.g., described above in connection withreference number 430).

As shown by reference number 455, the UE may decode the downlinkcommunication(s). In some aspects, the UE may use information includedin the indication that tone reservation is to be applied to thesubcarrier(s) (e.g., described above in connection with reference number430) to decode the downlink communication(s). In some aspects, the UEmay decode the downlink communication(s) based at least in part ondiscarding signals associated with the one or more subcarriers to whichtone reservation was applied (e.g., zeroing out LLRs of samplesassociated with the one or more subcarriers).

As indicated above, FIG. 4 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 4 .

FIG. 5 is a diagram illustrating an example 500 of subcarrier tonereservation, in accordance with the present disclosure. As shown in FIG.5 , a base station (e.g., base station 110) may communicate with a UE(e.g., UE 120). In some aspects, the base station and the UE may be partof a wireless network (e.g., wireless network 100). As shown in FIG. 5 ,the UE may apply tone reservation for uplink communications.

As shown by reference number 505, the UE may receive, and the basestation may transmit configuration information. In some aspects, the UEmay receive the configuration information via one or more of radioresource control (RRC) signaling, MAC control elements (MAC CEs), and/ordownlink control information (DCI), among other examples. In someaspects, the configuration information may include an indication of oneor more configuration parameters (e.g., already known to the UE) forselection by the UE, and/or explicit configuration information for theUE to use to configure the UE, among other examples.

In some aspects, the configuration information may indicate that the UEis to receive an indication that tone reservation is to be applied toone or more subcarriers for one or more uplink communications. Forexample, the configuration information may indicate that the UE is toreceive the indication via RRC signaling, MAC signaling, and/or DCI,among other examples. In some aspects, the indication may include anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, and/or a threshold power for subcarriers to which tonereservation is to be applied. In some aspects, the configurationinformation may indicate that the UE is to transmit one or more uplinksignals (e.g., sounding reference signals), using the one or moresubcarriers, for measurement by the base station. In some aspects, theconfiguration information may indicate that the UE is to receive one ormore downlink signals (e.g., CSI-RSs or SSBs, among other examples) anddetermine a channel response based at least in part on the one or moredownlink. In some aspects, the configuration information may indicatethat the UE is to apply tone reservation to the one or more subcarriersbased at least in part on received energy (e.g., power) on the one ormore subcarriers (e.g., based at least in part on the one or moresubcarriers having a lowest received energy of subcarriers of the one ormore downlink signals).

In some aspects, the configuration information may indicate that the UEis to transmit the one or more uplink communications having the tonereservation applied to the one or more subcarriers.

As shown by reference number 510, the UE may configure itself based atleast in part on the configuration information. In some aspects, the UEmay be configured to perform one or more operations described hereinbased at least in part on the configuration information.

As shown by reference number 515, the UE may transmit, and the basestation may receive, an indication of a UE capability to transmit uplinkcommunications having tone reservation applied based at least in part onone or more measurements of downlink signals. In some aspects, the UEmay transmit the indication as part of an RRC configuration process. Forexample, the UE may transmit the indication in connection with a UEcapability report during or after an RRC configuration process. In someaspects, the UE capability to transmit the uplink communications havingthe tone reservation applied may be based at least in part on aconfiguration of the UE, components of the UE, and/or availability ofresources of the UE that may be used to determine the one or moresubcarriers, within a threshold amount of time, to which tonereservation is to be applied.

As shown by reference number 520, the UE may transmit, and the basestation may receive, one or more uplink signals. In some aspects, theone or more uplink signals may be transmitted by the UE for measurementby the base station (e.g., to enable the base station to determinewhether tone reservation is to be applied to uplink communications). Insome aspects, the one or more uplink signals include one or moresounding reference signals (SRSs).

As shown by reference number 525, the base station may transmit, and theUE may receive, an indication that tone reservation is to be applied toone or more subcarriers for one or more uplink communications. In someaspects, the UE may receive the indication (e.g., MAC-CE with a slotoffset between a downlink allocation and corresponding data (KO) greaterthan or equal to 0) via RRC signaling, MAC signaling, and/or DCI, amongother examples. In some aspects, the indication that tone reservation isto be applied to one or more subcarriers for one or more uplinkcommunications may have one or more characteristics in common with theindication that tone reservation is to be applied to one or moresubcarriers for one or more downlink communications described inconnection with reference number 430 of FIG. 4 .

As shown by reference number 530, the UE may receive, and the basestation may transmit, one or more downlink signals. In some aspects, theone or more downlink signals may be transmitted by the base station formeasurement by the UE (e.g., to enable the UE to identify subcarriers towhich tone reservation is to be applied). In some aspects, the one ormore downlink signals may include one or more CSI-RSs, SSBs, or datachannel signaling, among other examples. In some aspects, the UE mayestimate a channel based at least in part on DMRSs within a data channeland/or within a control channel to estimate a downlink channel. Forexample, the UE may estimate the channel (e.g., the uplink channel)based at least in part on an assumption of reciprocity with the downlinkchannel.

As shown by reference number 535, the UE may apply tone reservation toone or more subcarriers based at least in part on received energy on theone or more downlink signals. In some aspects, the UE may determinechannel conditions (e.g., received energy measurements, one or more SINRvalues, and/or one or more PAPR values, among other examples) based atleast in part on the one or more downlink signals and apply tonereservation based at least in part on the channel conditions. In someaspects, the UE may apply tone reservation to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more downlinksignals.

As shown by reference number 540, the UE may transmit, and the basestation may receive, the one or more uplink communications having thetone reservation applied to the one or more subcarriers. In someaspects, one or more subcarriers to which tone reservation is applied(e.g., by the UE) are based at least in part on the measurement of theone or more downlink signals on the one or more subcarriers (e.g., asdescribed herein).

As shown by reference number 545, the base station may determine achannel response of the one or more uplink communications and/or thattone reservation is applied to the one or more subcarriers based atleast in part on received energy on the one or more subcarriers (e.g.,as described in connection with reference number 450). In some aspects,the base station may determine that tone reservation is applied to theone or more uplink communications based at least in part on theconfiguration information (e.g., described above in connection withreference number 505) or based at least in part on the indication thattone reservation is to be applied (e.g., described above in connectionwith reference number 525), among other examples. In some aspects, thebase station may determine the channel response based at least in parton DMRSs of the one or more uplink communications (e.g., based at leastin part on an estimation of the lowest energy subcarriers using theDMRSs).

As shown by reference number 550, the base station may decode the one ormore uplink communications. In some aspects, the base station may useinformation included in the indication that tone reservation is to beapplied to the one or more subcarriers (e.g., described above inconnection with reference number 525) to decode the one or more uplinkcommunications. In some aspects, the base station may decode the one ormore uplink communications based at least in part on discarding signalsassociated with the one or more subcarriers to which tone reservationwas applied (e.g., zeroing out LLRs of samples associated with the oneor more subcarriers).

In this way, the base station and UE may communicate using tonereservation without the need to transmit reports to identify specificsubcarriers to which tone reservation is to be applied. This may reduceoverhead associated with the use of tone reservation by obviating theneed to transmit reports for tone reservation, which may increasethroughput between the UE and the base station. In addition, theapplication of tone reservation may lead to improved PAPR, which mayconserve resources that the base station uses to receive (e.g.,demodulate, decode, and/or the like) the uplink communication and mayalso lead to improved efficiency of power amplification at the UE (e.g.,by conserving power that would otherwise be used to transmit reservedsubcarriers).

As indicated above, FIG. 5 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 5 .

FIG. 6 is a diagram illustrating an example 600 of subcarrier tonereservation, in accordance with the present disclosure. As shown in FIG.6 , tone reservation may be applied to communications transmitted from abase station to a UE.

As shown in example 600, the base station may measure one or more UESRSs to estimate an uplink channel. The base station may use theestimate of the uplink channel to estimate a downlink channel (e.g.,using an assumption of reciprocity between the uplink channel and thedownlink channel). In some aspects, the base station may use theestimate of the downlink channel to determine subcarriers to which tonereservation is to be applied.

The base station may determine that tone reservation is to be applied toone or more subcarriers for downlink transmissions to the UE (e.g.,based at least in part on an SINR reported by the UE, the uplink channelestimate, other metrics associated with the uplink channel or thedownlink channel, network traffic, and/or an amount of data buffered fortransmission to the UE). When the base station determines that tonereservation is to be applied, the base station may then determine whichsubcarriers are to be selected for tone reservation. In some aspects,selection of subcarriers may be based at least in part on a defaultnumber, such as the lowest 10% of subcarriers . In some aspects,selection of the default number may be based at least in part on theSINR measurements.

As shown by reference number 610, in some aspects, the base station mayiteratively perform subcarrier selection techniques until a thresholdPAPR value is reached. For example, the base station may use the UEdownlink channel estimate, a default number of tones (e.g.,subcarriers), and a default PAPR threshold to perform a selectivemapping (SLM) technique, where alternative transmit sequence vectors(e.g., corresponding to the UE downlink channel) are generated from thesame data source by multiplying the vectors by a random or pseudo-randomphase. After multiplication, inverse fast Fourier transform (IFFT) maybe performed on the vectors to convert the corresponding signal from thefrequency domain to the time domain, and PAPR values may be determinedfor each of the vectors. The PAPR values may be compared to one anotherin a manner designed to optimize tone reservation values by identifyinga vector having tone reservations that result in a relatively low, orlowest, PAPR value with respect to other vectors. The base station maythen determine whether the PAPR threshold is satisfied by the tonereservations indicated in the identified vector.

In some aspects, the subcarrier selection process may be performed up tok iterations, where k is a positive integer, and/or until a PAPR valuethat satisfies the threshold is reached. For example, if a default value(e.g., an initial value) for the number of subcarriers to which tonereservation is to be applied is 5%, and the subcarrier selection outputfails to satisfy the PAPR threshold by applying tone reservation to thelowest 5% of subcarriers, the base station may increase the defaultvalue (e.g., by a fixed amount, variable amount, or fixed rate) andperform SLM again to determine if reserving the increased number ofsubcarriers (e.g., the lowest 6%) will satisfy the PAPR threshold. Insome aspects, the PAPR threshold may be modified (e.g., lowered todecrease the number of subcarriers that would be reserved, or raised toincrease the number of subcarriers that would be reserved) wheniterating through the subcarrier selection process.

Once a tone reservation satisfying the PAPR threshold is identified, thebase station may use the identified tone reservation and modulated datato remap the modulated data using the identified tone reservation scheme(e.g., application of tone reservation on the identified subchannels).For example, in a situation where the subcarrier selection processindicates that the lowest 6% of subcarriers (e.g., in terms of SINR)should be reserved to meet a given PAPR threshold, the modulated datamay only be mapped to the top 94% subcarriers (e.g., based on receivedenergy and/or power), leaving the bottom 6% reserved. After applicationof IFFT, the resulting downlink communication may be transmitted to theUE.

The UE may receive the downlink communication as radio frequency (RF)signals, and may use analog to digital conversion (ADC), using aconfigured number of bits, to provide digital output to a digital frontend (DFE) of the UE. The UE may then apply a fast Fourier transform(FFT) algorithm to convert the received signals to a frequency domainand obtain the UE downlink communication (e.g., DMRSs).

The UE may decode a report of the tone reservation (e.g., included inDCI), which may indicate a number of subcarriers to which tonereservation was applied. For example, the report may indicate that tonereservation is to be applied to the lowest 6% of subcarriers.

The UE may use the downlink communication (e.g., DMRS) to estimate theenergy (e.g., power) of the subcarriers of the channel (e.g., usingSINR). After identifying the smallest (e.g., lowest) energy subcarriers(e.g., the bottom 6%), the UE may discard the identified subcarriers anddecode the remaining 94% of the data.

In this way, the base station and UE may communication using tonereservation without the need to transmit reports to identify specificsubcarriers to which tone reservation is to be applied. This may reduceoverhead associated with the use of tone reservation by obviating theneed to transmit reports for tone reservation, which may increasethroughput between the UE and base station. In addition, the applicationof tone reservation may lead to improved PAPR, which may conserveresources that the UE uses to receive (e.g., demodulate, decode, and/orthe like) the downlink transmission and may also lead to improvedefficiency of power amplification at the base station (e.g., byconserving power that would otherwise be used to transmit reservedsubcarriers).

As indicated above, FIG. 6 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 6 .

FIG. 7 is a diagram illustrating an example process 700 performed, forexample, by a UE, in accordance with the present disclosure. Exampleprocess 700 is an example where the UE (e.g., UE 120) performsoperations associated with techniques for subcarrier tone reservation.

As shown in FIG. 7 , in some aspects, process 700 may include receivingan indication that tone reservation is to be applied to one or moresubcarriers for one or more downlink communications (block 710). Forexample, the UE (e.g., using reception component 902, depicted in FIG. 9) may receive an indication that tone reservation is to be applied toone or more subcarriers for one or more downlink communications, asdescribed above.

As further shown in FIG. 7 , in some aspects, process 700 may includetransmitting one or more uplink signals, using the one or moresubcarriers, for measurement by a base station (block 720). For example,the UE (e.g., using transmission component 904, depicted in FIG. 9 ) maytransmit one or more uplink signals, using the one or more subcarriers,for measurement by a base station, as described above.

As further shown in FIG. 7 , in some aspects, process 700 may includereceiving the one or more downlink communications having the tonereservation applied to the one or more subcarriers, the one or moresubcarriers having tone reservation applied based at least in part onthe measurement of the one or more uplink signals on the one or moresubcarriers (block 730). For example, the UE (e.g., using receptioncomponent 902, depicted in FIG. 9 ) may receive the one or more downlinkcommunications having the tone reservation applied to the one or moresubcarriers, the one or more subcarriers having tone reservation appliedbased at least in part on the measurement of the one or more uplinksignals on the one or more subcarriers, as described above.

Process 700 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, the reception of the indication that tone reservationis to be applied to the one or more subcarriers for one or more downlinkcommunications comprises receiving the indication that tone reservationis to be applied to the one or more subcarriers for one or more downlinkcommunications via one or more of radio resource control signaling,medium access control signaling, or downlinking control information.

In a second aspect, alone or in combination with the first aspect, theindication that tone reservation is to be applied to the one or moresubcarriers for the one or more downlink communications comprises one ormore of an indication of a number of subcarriers to which tonereservation is to be applied, a fraction of subcarriers to which tonereservation is to be applied, or a threshold power for subcarriers towhich tone reservation is to be applied.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the one or more uplink signals comprise one or moresounding reference signals.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, process 700 includes determining (e.g.,using communication manager 908, depicted in FIG. 9 ) a channel responseof the one or more downlink communications, and determining that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, the determination of the channel response of theone or more downlink communications comprises determining the channelresponse based at least in part on demodulation reference signals of theone or more downlink communications.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, the determination that tone reservation isapplied to the one or more subcarriers based at least in part onreceived energy on the one or more subcarriers comprises determiningthat tone reservation is applied to the one or more subcarriers based atleast in part on the one or more subcarriers having a lowest receivedenergy of subcarriers of the one or more downlink communications.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, process 700 includes decoding (e.g., usingcommunication manager 908, depicted in FIG. 9 ) the one or more downlinkcommunication based at least in part on discarding signals associatedwith the one or more subcarriers.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, process 700 includes transmitting (e.g.,using transmission component 904, depicted in FIG. 9 ) an indication ofa measurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on reception of one or more downlink referencesignals.

Although FIG. 7 shows example blocks of process 700, in some aspects,process 700 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 7 .Additionally, or alternatively, two or more of the blocks of process 700may be performed in parallel. As indicated above, in some aspects, aprocess similar to a portion or all of process 700 may be performed(e.g., by a UE) for the application of tone reservation to uplinksignals.

FIG. 8 is a diagram illustrating an example process 800 performed, forexample, by a base station, in accordance with the present disclosure.Example process 800 is an example where the base station (e.g., basestation 110) performs operations associated with techniques forsubcarrier tone reservation.

As shown in FIG. 8 , in some aspects, process 800 may includetransmitting an indication that tone reservation is to be applied to oneor more subcarriers for one or more downlink communications (block 810).For example, the base station (e.g., using transmission component 1004,depicted in FIG. 10 ) may transmit an indication that tone reservationis to be applied to one or more subcarriers for one or more downlinkcommunications, as described above.

As further shown in FIG. 8 , in some aspects, process 800 may includereceiving one or more uplink signals for measurement by a base station(block 820). For example, the base station (e.g., using receptioncomponent 1002, depicted in FIG. 10 ) may receive one or more uplinksignals for measurement by a base station, as described above.

As further shown in FIG. 8 , in some aspects, process 800 may includetransmitting the one or more downlink communications having tonereservation applied to the one or more subcarriers, the one or moresubcarriers having tone reservation applied based at least in part onthe measurement of the one or more uplink signals on the one or moresubcarriers (block 830). For example, the base station (e.g., usingtransmission component 1004, depicted in FIG. 10 ) may transmit the oneor more downlink communications having tone reservation applied to theone or more subcarriers, the one or more subcarriers having tonereservation applied based at least in part on the measurement of the oneor more uplink signals on the one or more subcarriers, as describedabove.

Process 800 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, the transmission of the indication that tonereservation is to be applied to the one or more subcarriers for one ormore downlink communications comprises transmitting the indication thattone reservation is to be applied to the one or more subcarriers for oneor more downlink communications via one or more of radio resourcecontrol signaling, medium access control signaling, or downlinkingcontrol information.

In a second aspect, alone or in combination with the first aspect, theindication that tone reservation is to be applied to the one or moresubcarriers for the one or more downlink communications comprises one ormore of an indication of a number of subcarriers to which tonereservation is to be applied, a fraction of subcarriers to which tonereservation is to be applied, or a threshold power for subcarriers towhich tone reservation is to be applied.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the one or more uplink signals comprise one or moresounding reference signals.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, process 800 includes determining (e.g.,using communication manager 1008, depicted in FIG. 10 ) channelconditions based at least in part on the one or more uplink signals, andapplying tone reservation to the one or more subcarriers based at leastin part on received energy, of the one or more uplink signals, on theone or more subcarriers.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, applying tone reservation to the one or moresubcarriers based at least in part on received energy, of the one ormore uplink signals, on the one or more subcarriers comprises applyingtone reservation to the one or more subcarriers based at least in parton the one or more subcarriers having a lowest received energy ofsubcarriers of the one or more uplink signals.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, process 800 includes receiving (e.g., usingreception component 1002, depicted in FIG. 10 ) an indication of ameasurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on transmission (e.g., using transmissioncomponent 1004, depicted in FIG. 10 ) of one or more downlink referencesignals, wherein the one or more subcarriers have tone reservationapplied based at least in part on the indication of the measurement ofthe one or more signal-to-interference-plus-noise ratios.

Although FIG. 8 shows example blocks of process 800, in some aspects,process 800 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 8 .Additionally, or alternatively, two or more of the blocks of process 800may be performed in parallel. As indicated above, in some aspects, aprocess similar to a portion or all of process 800 may be performed(e.g., by a UE) for the application of tone reservation to uplinksignals.

FIG. 9 is a block diagram of an example apparatus 900 for wirelesscommunication. The apparatus 900 may be a UE, or a UE may include theapparatus 900. In some aspects, the apparatus 900 includes a receptioncomponent 902 and a transmission component 904, which may be incommunication with one another (for example, via one or more busesand/or one or more other components). As shown, the apparatus 900 maycommunicate with another apparatus 906 (such as a UE, a base station, oranother wireless communication device) using the reception component 902and the transmission component 904. As further shown, the apparatus 900may include a communication manager 908 configured to perform one ormore of the operations described herein in connection with FIGS. 3-6 .

In some aspects, the apparatus 900 may be configured to perform one ormore operations described herein in connection with FIGS. 3-6 .Additionally, or alternatively, the apparatus 900 may be configured toperform one or more processes described herein, such as process 700 ofFIG. 7 . In some aspects, the apparatus 900 and/or one or morecomponents shown in FIG. 9 may include one or more components of the UEdescribed above in connection with FIG. 2 . Additionally, oralternatively, one or more components shown in FIG. 9 may be implementedwithin one or more components described above in connection with FIG. 2. Additionally, or alternatively, one or more components of the set ofcomponents may be implemented at least in part as software stored in amemory. For example, a component (or a portion of a component) may beimplemented as instructions or code stored in a non-transitorycomputer-readable medium and executable by a controller or a processorto perform the functions or operations of the component.

The reception component 902 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 906. The reception component 902may provide received communications to one or more other components ofthe apparatus 900. In some aspects, the reception component 902 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus906. In some aspects, the reception component 902 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the UEdescribed above in connection with FIG. 2 .

The transmission component 904 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 906. In some aspects, one or moreother components of the apparatus 906 may generate communications andmay provide the generated communications to the transmission component904 for transmission to the apparatus 906. In some aspects, thetransmission component 904 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 906. In some aspects, the transmission component 904may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the UE described above in connection with FIG. 2. In some aspects, the transmission component 904 may be co-located withthe reception component 902 in a transceiver.

The reception component 902 may receive an indication that tonereservation is to be applied to one or more subcarriers for one or moredownlink communications. The transmission component 904 may transmit oneor more uplink signals, using the one or more subcarriers, formeasurement by a base station. The reception component 902 may receivethe one or more downlink communications having the tone reservationapplied to the one or more subcarriers, the one or more subcarriershaving tone reservation applied based at least in part on themeasurement of the one or more uplink signals on the one or moresubcarriers.

The communication manager 908 may determine a channel response of theone or more downlink communications.

The communication manager 908 may determine that tone reservation isapplied to the one or more subcarriers based at least in part onreceived energy on the one or more subcarriers.

The communication manager 908 may decode the one or more downlinkcommunication based at least in part on discarding signals associatedwith the one or more subcarriers.

The transmission component 904 may transmit an indication of ameasurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on reception of one or more downlink referencesignals.

The number and arrangement of components shown in FIG. 9 are provided asan example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 9 . Furthermore, two or more components shownin FIG. 9 may be implemented within a single component, or a singlecomponent shown in FIG. 9 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 9 may perform one or more functions describedas being performed by another set of components shown in FIG. 9 .

FIG. 10 is a block diagram of an example apparatus 1000 for wirelesscommunication. The apparatus 1000 may be a base station, or a basestation may include the apparatus 1000. In some aspects, the apparatus1000 includes a reception component 1002 and a transmission component1004, which may be in communication with one another (for example, viaone or more buses and/or one or more other components). As shown, theapparatus 1000 may communicate with another apparatus 1006 (such as aUE, a base station, or another wireless communication device) using thereception component 1002 and the transmission component 1004. As furthershown, the apparatus 1000 may include a communication manager 1008configured to perform one or more operations described herein inconnection with FIGS. 3-6 .

In some aspects, the apparatus 1000 may be configured to perform one ormore operations described herein in connection with FIGS. 3-6 .Additionally, or alternatively, the apparatus 1000 may be configured toperform one or more processes described herein, such as process 800 ofFIG. 8 . In some aspects, the apparatus 1000 and/or one or morecomponents shown in FIG. 10 may include one or more components of thebase station described above in connection with FIG. 2 . Additionally,or alternatively, one or more components shown in FIG. 10 may beimplemented within one or more components described above in connectionwith FIG. 2 . Additionally, or alternatively, one or more components ofthe set of components may be implemented at least in part as softwarestored in a memory. For example, a component (or a portion of acomponent) may be implemented as instructions or code stored in anon-transitory computer-readable medium and executable by a controlleror a processor to perform the functions or operations of the component.

The reception component 1002 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1006. The reception component1002 may provide received communications to one or more other componentsof the apparatus 1000. In some aspects, the reception component 1002 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus1006. In some aspects, the reception component 1002 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the basestation described above in connection with FIG. 2 .

The transmission component 1004 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1006. In some aspects, one or moreother components of the apparatus 1006 may generate communications andmay provide the generated communications to the transmission component1004 for transmission to the apparatus 1006. In some aspects, thetransmission component 1004 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 1006. In some aspects, the transmission component 1004may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the base station described above in connectionwith FIG. 2 . In some aspects, the transmission component 1004 may beco-located with the reception component 1002 in a transceiver.

The transmission component 1004 may transmit an indication that tonereservation is to be applied to one or more subcarriers for one or moredownlink communications. The reception component 1002 may receive one ormore uplink signals for measurement by a base station. The transmissioncomponent 1004 may transmit the one or more downlink communicationshaving tone reservation applied to the one or more subcarriers, the oneor more subcarriers having tone reservation applied based at least inpart on the measurement of the one or more uplink signals on the one ormore subcarriers.

The communication manager 1008 may determine channel conditions based atleast in part on the one or more uplink signals.

The communication manager 1008 and/or the transmission component 1004may apply tone reservation to the one or more subcarriers based at leastin part on received energy, of the one or more uplink signals, on theone or more subcarriers.

The reception component 1002 may receive an indication of a measurementof one or more signal-to-interference-plus-noise ratios based at leastin part on transmission of one or more downlink reference signalswherein the one or more subcarriers have tone reservation applied basedat least in part on the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

The number and arrangement of components shown in FIG. 10 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 10 . Furthermore, two or more components shownin FIG. 10 may be implemented within a single component, or a singlecomponent shown in FIG. 10 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 10 may perform one or more functions describedas being performed by another set of components shown in FIG. 10 .

The following provides an overview of some Aspects of the presentdisclosure:

Aspect 1: A method of wireless communication performed by a userequipment (UE), comprising: receiving an indication that tonereservation is to be applied to one or more subcarriers for one or moredownlink communications; transmitting one or more uplink signals, usingthe one or more subcarriers, for measurement by a base station; andreceiving the one or more downlink communications having the tonereservation applied to the one or more subcarriers, the one or moresubcarriers having tone reservation applied based at least in part onthe measurement of the one or more uplink signals on the one or moresubcarriers.

Aspect 2: The method of Aspect 1, wherein the reception of theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications comprises: receivingthe indication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications via one or more of:radio resource control signaling, medium access control signaling, ordownlink control information.

Aspect 3: The method of any of Aspects 1-2, wherein the indication thattone reservation is to be applied to the one or more subcarriers for theone or more downlink communications comprises one or more of: anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, or a threshold power for subcarriers to which tone reservationis to be applied.

Aspect 4: The method of any of Aspects 1-3, wherein the one or moreuplink signals comprise one or more sounding reference signals.

Aspect 5: The method of any of Aspects 1-4, further comprising:determining a channel response of the one or more downlinkcommunications; and determining that tone reservation is applied to theone or more subcarriers based at least in part on received energy on theone or more subcarriers.

Aspect 6: The method of Aspect 5, wherein the determination of thechannel response of the one or more downlink communications comprises:determining the channel response based at least in part on demodulationreference signals of the one or more downlink communications.

Aspect 7: The method of Aspect 5, wherein the determination that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers comprises:determining that tone reservation is applied to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more downlinkcommunications.

Aspect 8: The method of any of Aspects 1-7, further comprising: decodingthe one or more downlink communication based at least in part ondiscarding signals associated with the one or more subcarriers.

Aspect 9: The method of any of Aspects 1-8, further comprising:transmitting an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.

Aspect 10: A method of wireless communication performed by a basestation, comprising: transmitting an indication that tone reservation isto be applied to one or more subcarriers for one or more downlinkcommunications; receiving one or more uplink signals for measurement bya base station; and transmitting the one or more downlink communicationshaving tone reservation applied to the one or more subcarriers, the oneor more subcarriers having tone reservation applied based at least inpart on the measurement of the one or more uplink signals on the one ormore subcarriers.

Aspect 11: The method of Aspect 10, wherein the transmission of theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications comprises:transmitting the indication that tone reservation is to be applied tothe one or more subcarriers for one or more downlink communications viaone or more of: radio resource control signaling, medium access controlsignaling, or downlink control information.

Aspect 12: The method of any of Aspects 10-11, wherein the indicationthat tone reservation is to be applied to the one or more subcarriersfor the one or more downlink communications comprises one or more of: anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, or a threshold power for subcarriers to which tone reservationis to be applied.

Aspect 13: The method of any of Aspects 10-12, wherein the one or moreuplink signals comprise one or more sounding reference signals.

Aspect 14: The method of any of Aspects 10-13, further comprising:determining channel conditions based at least in part on the one or moreuplink signals; and applying tone reservation to the one or moresubcarriers based at least in part on received energy, of the one ormore uplink signals, on the one or more subcarriers.

Aspect 15: The method of Aspect 14, wherein applying tone reservation tothe one or more subcarriers based at least in part on received energy,of the one or more uplink signals, on the one or more subcarrierscomprises: applying tone reservation to the one or more subcarriersbased at least in part on the one or more subcarriers having a lowestreceived energy of subcarriers of the one or more uplink signals.

Aspect 16: The method of any of Aspects 10-15, further comprising:receiving an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.

Aspect 17: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more Aspects ofAspects 1-9.

Aspect 18: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more Aspectsof Aspects 1-9.

Aspect 19: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more Aspects of Aspects1-9.

Aspect 20: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more Aspects of Aspects 1-9.

Aspect 21: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore Aspects of Aspects 1-9.

Aspect 22: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more Aspects ofAspects 10-16.

Aspect 23: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more Aspectsof Aspects 10-16.

Aspect 24: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more Aspects of Aspects10-16.

Aspect 25: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more Aspects of Aspects 10-16.

Aspect 26: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore Aspects of Aspects 10-16.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseforms disclosed. Modifications and variations may be made in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware, firmware, and/or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, and/or acombination of hardware and software. It will be apparent that systemsand/or methods described herein may be implemented in different forms ofhardware, firmware, and/or a combination of hardware and software. Theactual specialized control hardware or software code used to implementthese systems and/or methods is not limiting of the aspects. Thus, theoperation and behavior of the systems and/or methods were describedherein without reference to specific software code—it being understoodthat software and hardware can be designed to implement the systemsand/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, or thelike.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. As used herein, a phrase referringto “at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well asany combination with multiples of the same element (e.g., a-a, a-a-a,a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or anyother ordering of a, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterms “set” and “group” are intended to include one or more items (e.g.,related items, unrelated items, or a combination of related andunrelated items), and may be used interchangeably with “one or more.”Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” or the like are intended to be open-ended terms. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise. Also, as used herein, the term “or”is intended to be inclusive when used in a series and may be usedinterchangeably with “and/or,” unless explicitly stated otherwise (e.g.,if used in combination with “either” or “only one of”).

What is claimed is:
 1. A user equipment (UE) for wireless communication,comprising: a memory; and one or more processors, operatively coupled tothe memory, configured to: receive an indication that tone reservationis to be applied to one or more subcarriers for one or more downlinkcommunications; transmit one or more uplink signals, using the one ormore subcarriers, for measurement by a base station; and receive the oneor more downlink communications having the tone reservation applied tothe one or more subcarriers, the one or more subcarriers having tonereservation applied based at least in part on the measurement of the oneor more uplink signals on the one or more subcarriers.
 2. The UE ofclaim 1, wherein the one or more processors, when receiving theindication that tone reservation is to be applied to the one or moresubcarriers for one or more downlink communications, are configured to:receive the indication that tone reservation is to be applied to the oneor more subcarriers for one or more downlink communications via one ormore of: radio resource control signaling, medium access controlsignaling, or downlink control information.
 3. The UE of claim 1,wherein the indication that tone reservation is to be applied to the oneor more subcarriers for the one or more downlink communicationscomprises one or more of: an indication of a number of subcarriers towhich tone reservation is to be applied, a fraction of subcarriers towhich tone reservation is to be applied, or a threshold power forsubcarriers to which tone reservation is to be applied.
 4. The UE ofclaim 1, wherein the one or more uplink signals comprise one or moresounding reference signals.
 5. The UE of claim 1, wherein the one ormore processors are further configured to: determine a channel responseof the one or more downlink communications; and determine that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers.
 6. The UE ofclaim 5, wherein the one or more processors, when determining thechannel response of the one or more downlink communications, areconfigured to: determine the channel response based at least in part ondemodulation reference signals of the one or more downlinkcommunications.
 7. The UE of claim 5, wherein the one or moreprocessors, when determining that tone reservation is applied to the oneor more subcarriers based at least in part on received energy on the oneor more subcarriers, are configured to: determine that tone reservationis applied to the one or more subcarriers based at least in part on theone or more subcarriers having a lowest received energy of subcarriersof the one or more downlink communications.
 8. The UE of claim 1,wherein the one or more processors are further configured to: decode theone or more downlink communication based at least in part on discardingsignals associated with the one or more subcarriers.
 9. The UE of claim1, wherein the one or more processors are further configured to:transmit an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.
 10. A base stationfor wireless communication, comprising: a memory; and one or moreprocessors, operatively coupled to the memory, configured to: transmitan indication that tone reservation is to be applied to one or moresubcarriers for one or more downlink communications; receive one or moreuplink signals for measurement by a base station; and transmit the oneor more downlink communications having tone reservation applied to theone or more subcarriers, the one or more subcarriers having tonereservation applied based at least in part on the measurement of the oneor more uplink signals on the one or more subcarriers.
 11. The basestation of claim 10, wherein the one or more processors, whentransmitting the indication that tone reservation is to be applied tothe one or more subcarriers for one or more downlink communications, areconfigured to: transmit the indication that tone reservation is to beapplied to the one or more subcarriers for one or more downlinkcommunications via one or more of: radio resource control signaling,medium access control signaling, or downlink control information. 12.The base station of claim 10, wherein the indication that tonereservation is to be applied to the one or more subcarriers for the oneor more downlink communications comprises one or more of: an indicationof a number of subcarriers to which tone reservation is to be applied, afraction of subcarriers to which tone reservation is to be applied, or athreshold power for subcarriers to which tone reservation is to beapplied.
 13. The base station of claim 10, wherein the one or moreuplink signals comprise one or more sounding reference signals.
 14. Thebase station of claim 10, wherein the one or more processors are furtherconfigured to: determine channel conditions based at least in part onthe one or more uplink signals; and apply tone reservation to the one ormore subcarriers based at least in part on received energy, of the oneor more uplink signals, on the one or more subcarriers.
 15. The basestation of claim 14, wherein the one or more processors, when applyingtone reservation to the one or more subcarriers based at least in parton received energy, of the one or more uplink signals, on the one ormore subcarriers comprises: apply tone reservation to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more uplinksignals.
 16. The base station of claim 10, wherein the one or moreprocessors are further configured to: receive an indication of ameasurement of one or more signal-to-interference-plus-noise ratiosbased at least in part on transmission of one or more downlink referencesignals, wherein the one or more subcarriers have tone reservationapplied based at least in part on the indication of the measurement ofthe one or more signal-to-interference-plus-noise ratios.
 17. A methodof wireless communication performed by a user equipment (UE),comprising: receiving an indication that tone reservation is to beapplied to one or more subcarriers for one or more downlinkcommunications; transmitting one or more uplink signals, using the oneor more subcarriers, for measurement by a base station; and receivingthe one or more downlink communications having the tone reservationapplied to the one or more subcarriers, the one or more subcarriershaving tone reservation applied based at least in part on themeasurement of the one or more uplink signals on the one or moresubcarriers.
 18. The method of claim 17, wherein the indication thattone reservation is to be applied to the one or more subcarriers for theone or more downlink communications comprises one or more of: anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, or a threshold power for subcarriers to which tone reservationis to be applied.
 19. The method of claim 17, wherein the one or moreuplink signals comprise one or more sounding reference signals.
 20. Themethod of claim 17, further comprising: determining a channel responseof the one or more downlink communications; and determining that tonereservation is applied to the one or more subcarriers based at least inpart on received energy on the one or more subcarriers.
 21. The methodof claim 20, wherein the determination of the channel response of theone or more downlink communications comprises: determining the channelresponse based at least in part on demodulation reference signals of theone or more downlink communications.
 22. The method of claim 20, whereinthe determination that tone reservation is applied to the one or moresubcarriers based at least in part on received energy on the one or moresubcarriers comprises: determining that tone reservation is applied tothe one or more subcarriers based at least in part on the one or moresubcarriers having a lowest received energy of subcarriers of the one ormore downlink communications.
 23. The method of claim 17, furthercomprising: decoding the one or more downlink communication based atleast in part on discarding signals associated with the one or moresubcarriers.
 24. The method of claim 17, further comprising:transmitting an indication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part onreception of one or more downlink reference signals.
 25. A method ofwireless communication performed by a base station, comprising:transmitting an indication that tone reservation is to be applied to oneor more subcarriers for one or more downlink communications; receivingone or more uplink signals for measurement by a base station; andtransmitting the one or more downlink communications having tonereservation applied to the one or more subcarriers, the one or moresubcarriers having tone reservation applied based at least in part onthe measurement of the one or more uplink signals on the one or moresubcarriers.
 26. The method of claim 25, wherein the indication thattone reservation is to be applied to the one or more subcarriers for theone or more downlink communications comprises one or more of: anindication of a number of subcarriers to which tone reservation is to beapplied, a fraction of subcarriers to which tone reservation is to beapplied, or a threshold power for subcarriers to which tone reservationis to be applied.
 27. The method of claim 25, wherein the one or moreuplink signals comprise one or more sounding reference signals.
 28. Themethod of claim 25, further comprising: determining channel conditionsbased at least in part on the one or more uplink signals; and applyingtone reservation to the one or more subcarriers based at least in parton received energy, of the one or more uplink signals, on the one ormore subcarriers.
 29. The method of claim 28, wherein applying tonereservation to the one or more subcarriers based at least in part onreceived energy, of the one or more uplink signals, on the one or moresubcarriers comprises: applying tone reservation to the one or moresubcarriers based at least in part on the one or more subcarriers havinga lowest received energy of subcarriers of the one or more uplinksignals.
 30. The method of claim 25, further comprising: receiving anindication of a measurement of one or moresignal-to-interference-plus-noise ratios based at least in part ontransmission of one or more downlink reference signals, wherein the oneor more subcarriers have tone reservation applied based at least in parton the indication of the measurement of the one or moresignal-to-interference-plus-noise ratios.